-LRB- CNN -RRB- -- Control of Tripoli International Airport changed hands Saturday evening , after an alliance of Islamist militias from around Libya seized the reins from a rival group .

Fighting was intense and spread from around the airport to other parts of Tripoli . Unknown fighter jets struck locations used by the alliance -- known as the Libya Dawn forces -- killing at least 12 Misrata militiamen , according to the Libyan state news agency , LANA .

Air traffic has been interrupted since the fighting began , with most international carriers suspending flights in and out of Libya .

The airport had previously been under the control of moderate militias from the western city of Zintan , who took control of it three years ago during the Libyan revolution , which toppled longtime dictator Moammar Gadhafi .

The takeover of the airport followed a more than a monthlong offensive dubbed `` Libya Dawn , '' the alliance said on social media .

Nearly three years after a revolution and NATO military intervention , Libya continues to be beset by instability -- politically , militarily and otherwise . That has included extensive violence , much of it involving increasingly powerful militias that have outgunned the North African nation 's central government .

Late last month , the U.S. Embassy in Tripoli , the United Nations and other international organizations and businesses evacuated their staffs due to the unrest .

U.S. Embassy in Libya evacuates personnel

The airport in Tripoli has long been a focal point of this fighting , as fighters tried to wrest control of it from the Zintan militia .

The head of Libya 's U.N. mission , Tarek Mitri , said in July that the stakes were high for all sides .

`` As the number of military actors mobilizing and consolidating their presence within the capital continues to grow , there is a mounting sense of a probable imminent and significant escalation in the conflict , '' Mitri said .

Fighting intensifies in Libya , airport control at stake

CNN 's Greg Botelho contributed to this report .

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Rival militias have been fighting for weeks in and around Tripoli 's airport

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An alliance of militias claims that it has taken the airport from a rival militia

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Militias are increasingly powerful , outgunning the central government